Telephone-receiver.



x ease of a telephone-receiver of hard rubber, the magnet mside the casebeing fastened to.

UNITED STATES PATENT oEEreE.

HENRY F. ALBRIGHT, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRICCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF v TELEPHONE-RECEIVER.

Application filed Febrlry 5, 1904. Serial No. 192.180.

and useful Improvement in Telephone-Re-- eeivers, of which the followingis a full, clear, Y

concise, and exact description.

My invention relates to a tele hone-receiver; and its object is toprovi` e an imroved receiver which will be cheap to manuacture andextremelyT efiicient.

It has been usual heretofore to make the the rear thereof, the' ear ieeescrewing over the outside of the front o the case to hold the diaphragmin position opposite the polar end of the magnet. This construction hasbeen rather expensive because of the amount of rubber required, andthere is the further and more serious objection that changes oftemperature will produce different degrees of expansion in the steelmagnet and inthe hardrubber case to which the magnet is fastened at therear and which supports the diaphragm in front, so that the dia hragm isnot mainv tained in a constant an unvarying relation to the magnet-pole.

My invention contem lates improvements in structure by which t eabove-mentioned objections are overcome and a further feature of myinvention contemplates an arrangement v by which it is made possible andpracticable to use a tubular magnet, which 1s the ideal form of magnetfor telephone-receivers, since it will act symmetrically upon thediaphragm.

I Will particularly described the preferred form of my invention byreference to the accompanying drawings, in Which- Figure 1 1s a sideview of my improved receiver. Fig. 2 is a longitudinal sectional viewvthereof. Fig. 3 is a view showing the several disassembled parts of thereceiver to illustrate how they are put together. Fig. 4 is a view, inpartia cross-section, on line 4 4 of Fig. 2. Fig. 5 is a cross-sectionalview on line 5 5 of F10. 2. Fig. 6 is a detail View of the disk to whicithe rear c'ap ofthe receiver is attached,l and Fig. 7 is a detail viewof the core and magnetizing-helix of the magnet.

The same letters of reference are used to designate the same partswherever they are shown.

- The tubular magnet comprises an outer shell or cylinder a and an innercore ci', magneticallyl united with the shell a at the rear by means ofa disk a?. The winding b is provided at the front end of the magnetsurrounding the core a inthe space between said core and the shell orcylinder a. Near the front of themagnet a non-ma ietic metallic cup cispermanently fastene upon the shell a, so that the polar ends of themagnet formed by the free ends of said core and shell are eoncentricallydisposed within said cup. The cup c is provided with a flange c, uponwhich the diaphragm d rests in operative relation to the concentricpoles of the tubular magnet. The core a and shell c are preferablypermanent magnets, forming, in effect, a permanent horseshoe-magnetwhich will be strong and less liable to deinagnetization, whose actionupon the diaphragm will be very symmetrical, and whose condition will bepermanent andconstant. It will be seen that these poles will act uponthe circular diaphragm symmetrically and will therefore lmake thetelephone-receiver more efficient than where two magnet-polesA aresimply placed side by side behind thediaphragm. The cup c being of metaland fastened to the metallic cylinder a of the magnet, it will be seenthat any variations in temperature will notlatfect th'e distance betweenthe magnetpole and the plane of the diaphragm, which should of course bekept constant ui order to lsecure the best results.

The rubber earpiece e fits against the end of the diaphragm and isprovided with threads upon its periphery. The earpiece is clamped 1nposition to hold the diaphragm against the flange c of the cup by meansof a metal clamping-ring f, which has an inner lip or rim at the rearadapted to engage the flange c of the cup and threads upon the forwardportion of the interior adapted to screw upon the threaded earpiece e.The several parts are thus securely fastened in position b screwing theclam i and earpiece together. t may be mentionedhere that thisconstruction is vextreemly effective to prevent tampering with thereceiver, since when the parts are tightly screwed together it ispractically irnpossible for an ordinary person to take them apart. Y

At the rear of the tubular magnet a threaded disk g is provided, uponwhich a metal cap Patented Get. 16, 1906.

h is adapted to screw. A11 insulating-block 7c, supporting terminalpieces k k2 for the conducting-wires which lead from the winding b,

is supported upon said disk g, the block and `disk being fastened to therear of the magnet by a screw Z. A bracket i, may be carried by. theinsulating-block, to which a tie-cord may be attached in a Well-knownmannerto relieve the conducting-Wires from strain. The terminal pieces7c k2 may be connected with studs k3 lc, passing through the block, towhich the Wires leading from the magnethelix may be attached.` Thescrews which carry the terminal pieces may be inserted in holes drilledthrough the block,vthe screwhole c for terminal c, however, alone beingshown in the drawings. lThe cap h is provided with a hole through whichthe flexible conducting-wires may be led to the terminal pieces upon theblock k.

A hard-'rubber shell lm may be slipped over the cylindrical portion a ofthe tubular magnet before the parts at the rear are assembled. A disk nmay be interposed between the disks a2 'and g to form a seat-or abutmentfor the rubber shell 'm and the cap h, and pins o o` maybe carried bythe disk a2, adapted to pass through the holes 'n' n in disk ln andholes g g in disk g into the block lr to prevent rotation of said parts:Holes g2 g2 are provided in disk g for the passage of theconductingwires leading from 'the helix to the terminals k k2. Aninsulating-disk p may -be' interposed between the insulating-block lcand disk g to prevent short-circuiting of the terminals on said disk,said disk being provided with holes p p for the passage of said pins 0o. The screw Z passes through block 7c, perforation p2 of disk p, holeg3 in disk g, hole n2 4in disk n, into the rear of the tubular magnet.

I claim- 1. In a telephone-receiver, the combination with a tubularmagnet having a magnetizing-helix surroundin .the core thereof, of adiaphragm supported efore the poles of said magnet, an insulating-blockcarrying termi- I nals for said helix lsecured at the rear of saidmagnet, and a cap secured at the rear of said magnet and inclosing saidblock and terminals, said cap having a hole therein to admit conductorsto said terminals.

2. In a telephone-receiver, the combination with a tubular magnet havinga magnetizing-helix surrounding a portion of the core thereof, of anon-magnetic cup flaring outwardly from the outer shell of said magnet,the free ends of said core and shell being concentrically disposedwithin the cup, a diaphragm supported over said cup in operativerelation tosai'd poles, means for clamping an earpiece uponsaidcup oversaid diaphragm, an insulatine-bleek secured to the re arof said magnetand aving terminals thereon for'said helix, and a cap secured betweenthe rear of said magnet and Said block and inclosingsaid block andterminals, said cap having an opening therein to admit conductors tosaidterminals.

3. In a telephone-receiver, the combination with a tubular magnet and amagnetizing-helix therefor, of a cup carried by said magnet at theforward end and supporting a diaphragm in operative relation to themagnet-pole, an earpiece and means for clamping the same upon the cu tohold the diaphragm in position, a har -rubber sleeve fitting over thebody of the magnet, a threaded disk of substantially the diameter of themagnet-cylinder fitting upon the rear end of said magnet, aninsulating-block having terminal pieces mounted thereon, a screwfastening the insulating-block and threaded disk to the rear end of themagnet-cylinder, and a cap fitting over said insulating-block andscrewing upon the threaded disk, said cap having a hole in its endthrough which iiexible conducting-wiresmay be passed to connect with theterminals upon said block.A

4. In a telephone-receiver, the combination with a tubular magnet havinga magnetizing-helix surrounding the core thereof, of a diaphragmsupported before the poles of said magnet, au insulated block secured atthe rear of said magnet, terminals for said helix carried by said block,and a cap inclosing said block andl terminals and secured in placebetween the vmagnet and insulated block, said cap havinga hole thereinto admit conductors to said terminals.

5. In a telephone-receiver, the combination with a tubular magnet and amagnetizing-helix surroundin the core thereof, of a diaphragm supportebefore the poles of said magnet, an insulating-block secured to therearl of said magnet, having terminals thereon for said helix, a diskinterposed between said block and magnet, and a cap fitting over saidblock and adapted to be secured to said disk, said cap having a holetherein to admit conductors to said terminals.

6. In a telephone-receiver, the combinartion with a tubular magnet, of acupfsecured to the shell of said ma et and flaring outwardly therefrom,the s ell being concentrically disposed Within'the cup, a diaphragm suorted by said cup opposite the poles of sai magnet, an earpiece, meansfor clamping said earpiece upon said cup over said diaphragm, aninsulating-block secured to the rear of said tubular magnet and carryingterminals for said helix, a disk secured between said block'and magnet,and a cap fitting over said block and adapted to be secured to saiddisk, said cap having a hole therein to admit conductors to saidterminals. l

7. In a telephone-receiver, the combination with a tubular rn'agnethavin a magnetizing-helix surrounding the'core t ereof, of a diaphragmsupported before the poles of said IOO IIO'

.magnet, an insulating-block at the rear of 13o said magnet and passing(said magnet having terminals thereon for said helix, pins connecting therear of said magnet with said block, a fastening member passing throughsaid block into the rear of said magnet, and a ca secured at the rear ofsaid magnet and inc osing said block, said cap having an opening thereinto admit conductors tosaid terminals.

` 8. In a telephone-receiver, the combination with a tubular magnethavin y a magnetizin -helix surrounding the core thereof, of a diaphragmsupported before the poles of said ma net, an insulating-block at therear of sai magnet and having terminals thereon for said helix, a diskinterposed between said block and magnet, pins secured to the rear ofinto the insulating-bloc a screw passing through said block and diskinto the rear of said ma net, and a metal cap fitting Vover said blocand secured to said disk, said cap having a hole therein to admitconductors to said terminals.

9. In a telephone-receiver, the combination with a central magnetqcore,of a magnetizing-helix surrounding a portion thereof, a.

tubular shell of magnetic material inclosing -upon the edge of thecup ino erative relation to the endsof said core an return polepiece, anearpiece iitting over the diaphragm aving threads u on its periphery, aninternally-threaded c amping-ring. engagin the` edge of the cup, saidclamping-ring eing adapted` to receive the earpiece, which screws into'the same, thereby clamping the diaphragm between the earpiece andthehrough said disk edge of the cup, an insulating-block secured to therear of said tubular magnet and carrying terminals for said helix, and a`cap secured between said ma et and block and inclosing said block anterminals, said cap having a hole therein to admit conductors to saidterminals.

10. In a telephone-receiver, the combination with a tubular magnethaving a magnetizing-helixsurrounding a portion of the core thereof, ofa diaphragm supported before the l'poles of said magnet, aninsulating-shell itting over said magnet, an insulating-block carryingterminals for said helix mounted at the rear of said magnet, and a metalcap h securedv at the rear of saidmagnet and inclosing said block, saidcap being secured in place between said block and magnet.

11. In a telephone-receiver, the combination with a tubular magnethaving a magnetizing-helix surrounding a portionof the core thereof, ofa non-magnetic metal cup united with the outer shell of said magnet, thefree ends of said core and shell being concentrically dis osed withinthe cup, a diaphragm clampe upon the edge of said cup, an insu-.lating-sleeve'iitting upon the shell .of said ma et and abuttingagainst the rear of sai Ucup, an insulated block carrying terminals forsaid helix su ported at the rear'of said magnet, a meta cap securedbetween said magnet and block and inclosing said 'block and terminals,and conductors leading thilough an opening in said cap to said terminas.

Y In witness 4whereof I hereunto subscribe my name this 25th day ofNovember, A. D.

HENRY F. ALBRIGHT. Witnesses:

-J BAUCKER, W. L. CoURsEN.

